Expandable impeller pump

Abstract

An impeller includes a hub, and a plurality of blades supported by the hub, the blades being arranged in at least two blade rows. The impeller has a deployed configuration in which the blades extend away from the hub, and a stored configuration in which at least one of the blades is radially compressed, for example by folding the blade towards the hub. The impeller may also have an operational configuration in which at least some of the blades are deformed from the deployed configuration upon rotation of the impeller when in the deployed configuration. The outer edge of one or more blades may have a winglet, and the base of the blades may have an associated indentation to facilitate folding of the blades.

1. An apparatus for inducing motion of a fluid relative to the apparatus, the apparatus comprising:
 an impeller, including:
 a hub extending in a length direction; and 
 a plurality of blades supported by the hub, each blade having a proximal end attached to the hub and a distal end; 
 the blades being arranged in at least two blade rows arranged in series in the length direction of the hub; 
 
 the impeller having a deployed configuration and a stored configuration, each blade in the deployed configuration of the impeller extending away from the hub, and at least one of the blades in the stored configuration of the impeller being compressed so as to move the distal end of the at least one blade towards the hub; and 
 an expandable sleeve including a matrix and a film disposed around the matrix, at least part of the impeller being located within the sleeve. 
 
     
     
       2. The apparatus as claimed in  claim 1 , wherein each blade row includes at least two blades. 
     
     
       3. The apparatus as claimed in  claim 1 , wherein the distal end of at least one of the plurality of blades includes a winglet. 
     
     
       4. The apparatus as claimed in  claim 1 , wherein the distal end of each blade in at least one blade row includes a winglet. 
     
     
       5. The apparatus as claimed in  claim 1 , wherein the distal end of each of the plurality of blades includes a winglet. 
     
     
       6. The apparatus as claimed in  claim 1 , wherein the blades are formed integrally with the hub. 
     
     
       7. The apparatus as claimed in  claim 1 , wherein the impeller has a first radius in the deployed configuration and a radius in the stored configuration which is less than half the first radius. 
     
     
       8. The apparatus as claimed in  claim 1 , wherein the matrix is formed from a shape memory material. 
     
     
       9. The apparatus as claimed in  claim 1 , wherein the film includes an elastic polymer. 
     
     
       10. The apparatus as claimed in  claim 1 , wherein the expandable sleeve has a storage configuration and an expanded configuration, the sleeve in the storage configuration having a diameter less than about  4  mm. 
     
     
       11. The apparatus as claimed in  claim 1 , wherein the expandable sleeve has an inlet end and a discharge end, the sleeve including a plurality of vanes arranged at the discharge end. 
     
     
       12. The apparatus as claimed in  claim 11 , wherein each of the plurality of vanes has an airfoil-shaped cross-section. 
     
     
       13. An apparatus for inducing motion of a fluid relative to the apparatus, the apparatus comprising:
 an impeller, including:
 a hub extending in a length direction; and 
 a plurality of blades supported by the hub, each blade having a proximal end attached to the hub and a distal end; 
 the blades being arranged in at least two blade rows arranged in series in the length direction of the hub; 
 
 the impeller having a deployed configuration, a stored configuration, and an operational configuration, each blade in the deployed configuration of the impeller extending away from the hub, at least one of the blades in the stored configuration of the impeller being compressed so as to move the distal end of the at least one blade towards the hub, and at least some of the blades in the operational configuration being deformed from the deployed configuration upon rotation of the impeller when in the deployed configuration; 
 wherein the impeller in the operational configuration is operable to pump about  4  liters of fluid per minute. 
 
     
     
       14. The apparatus as claimed in  claim 13 , wherein the impeller has a first radius in the deployed configuration and a second radius in the stored configuration which is less than half the first radius. 
     
     
       15. The apparatus as claimed in  claim 14 , wherein the impeller has a third radius in the operational configuration, the second radius being less than half the third radius. 
     
     
       16. An apparatus for inducing motion of a fluid relative to the apparatus, the apparatus comprising:
 an elongated cannula having a proximal portion and a distal portion, the proximal portion including a conduit having a fixed diameter, and the distal portion including an expandable conduit having a diameter expandable to a diameter greater than the fixed diameter, the conduit having a substantially constant transverse width along its length when expanded; 
 an impeller positioned in the elongated cannula and having a deployed configuration and a stored configuration, the impeller having substantially the same length in the deployed and stored configurations; and 
 a drive shaft operably coupled with the impeller at a proximal end thereof. 
 
     
     
       17. The apparatus of  claim 16 , wherein the impeller is compressed in the stored configuration so as to move the radially outward portion of the impeller towards the drive shaft. 
     
     
       18. The apparatus of  claim 16 , wherein the impeller comprises an axially-extending hub and at least two blades supported by the hub, the at least two blades being at least partially axially offset from each other. 
     
     
       19. An apparatus for inducing motion of a fluid, comprising:
 a drive shaft configured to be operably coupled with a motor; 
 an impeller having one or more impeller blades supported by and extending radially outward from an annular structure, the impeller having a blade region having a proximal end corresponding to the proximal end of the proximal-most impeller blade and a distal end corresponding to the distal end of the distal-most impeller blade, the annular structure being operably coupled with the drive shaft at a distal section of the drive shaft, wherein the impeller is configured to self-deploy into a deployed configuration from a compressed configuration; and 
 a housing having an expandable section that encompasses the impeller, wherein the housing comprises a mesh, wherein openings of the mesh are closed by an elastic covering disposed in at least a portion of the expandable section; 
 wherein a length between the proximal end and the distal end of the blade region is substantially the same when the impeller is in the deployed configuration and when the impeller is in the compressed configuration. 
 
     
     
       20. The apparatus of  claim 19 , wherein the housing is made of an elastic material such that, after forced compression, the impeller unfolds automatically. 
     
     
       21. The apparatus of  claim 19 , wherein the mesh of the housing is made of a flexible material. 
     
     
       22. The apparatus of  claim 21 , wherein the flexible material comprises at least one of nitinol and a polymer material. 
     
     
       23. The apparatus of  claim 19 , wherein the mesh of the housing is made of a flexible material. 
     
     
       24. The apparatus of  claim 19 , wherein the elastic covering of the pump housing comprises a polymer coating. 
     
     
       25. The apparatus of  claim 19 , wherein the polymer coating comprises polyurethane. 
     
     
       26. The apparatus of  claim 19 , further comprising an expandable outlet conduit disposed proximally of the impeller. 
     
     
       27. The apparatus of  claim 19 , wherein the drive shaft is at least partially housed within a sleeve.